Adsorption of Ethylene on Neutral, Anionic and Cationic Gold Clusters

TL;DR

This study uses density-functional theory to analyze how ethylene adsorbs on small neutral, anionic, and cationic gold clusters, revealing different bonding modes, size-dependent energies, and charge effects that influence adsorption behavior.

Contribution

It provides a detailed theoretical comparison of ethylene adsorption modes on various charged gold clusters, highlighting the role of electronic shell effects and charge in adsorption mechanisms.

Findings

Pi-bonded adsorption dominates over di-sigma mode in most cases.

Adsorption energy varies with cluster size and charge state.

Vibrational frequency shifts can distinguish adsorption modes.

Abstract

The adsorption of ethylene molecule on neutral, anionic and cationic gold clusters consisting of up to 10 atoms has been investigated using density-functional theory. It is demonstrated that C2H4 can be adsorbed on small gold clusters in two different configurations, corresponding to the pi- and di-sigma-bonded species. Adsorption in the pi-bonded mode dominates over the di-sigma mode over all considered cluster sizes n, with the exception of the neutral C2H4-Au5 system. A striking difference is found in the size-dependence of the adsorption energy of C2H4 bonded to the neutral gold clusters in the pi and di-sigma configurations. The important role of the electronic shell effects in the di-sigma mode of ethylene adsorption on neutral gold clusters is demonstrated. It is shown that the interaction of C2H4 with small gold clusters strongly depends on their charge. The typical shift in the vibrational frequencies of C2H4 adsorbed in the pi- and the di-sigma configurations gives a guidance to experimentally distinguish between the two modes of adsorption.